Once common in the Chesapeake Bay and other East Coast estuaries, Atlantic sturgeon levels are thought to be a fraction of what they were when settlers arrived in Jamestown more than 400 years ago — victims of overfishing, loss of habitat, pollution and ship strikes.

Conservation groups want the fish listed under the Endangered Species Act. But researchers and multiple state agencies oppose the effort. They favor a less strict designation, which they say will allow them to continue their research and prompt fewer restrictions on commercial fisheries.